Dynamic Modulation of Thymic MicroRNAs in Response to Stress
Physiological stress evokes rapid changes in both the innate and adaptive immune response. Immature αβ T cells developing in the thymus are particularly sensitive to stress, with infections and/or exposure to lipopolysaccharide (LPS) or glucocorticoids eliciting a rapid apoptotic program.
MicroRNAs are a class of small, non-coding RNAs that play a critical role in immune system by regulating/fine tuning the inflammatory response through regulation of global gene expression by targeting diverse mRNAs for degradation.
A team of researchers at the University of Texas Southwestern Medical Center set out to demonstrate that a subset of thymically encoded microRNAs would be stress responsive and modulate T cell production. They performed microRNA profiling (LC Sciences) of thymic microRNAs isolated from control or stressed thymic tissue obtained from mice.
They identified 18 microRNAs that are dysregulated >1.5-fold in response to LPS or the synthetic corticosteroid dexamethasone. These included miRs which have anti-apoptotic functions and which contribute to T cell tolerance. Many of the differentially regulated microRNAs have known functions in thymopoiesis, indicating that their dysregulation will alter T cell repertoire selection and the formation of naïve T cells.
This data has implications for clinical treatments involving anti-inflammatory steroids, ablation therapies, and provides mechanistic insights into the consequences of infections.
- Belkaya S, Silge RL, Hoover AR, Medeiros JJ, Eitson JL, et al. (2011) Dynamic Modulation of Thymic MicroRNAs in Response to Stress. PLoS ONE 6(11), e27580. [article]
Standard Data Analysis Report – Generated by the LC Science microRNA Microarray Service